Mining-machine



No. 261,608; Patel 113631 July 25, 1882 INVENTOR WITNESSES: Z(@%. $32M.

machine and controlling its movements byihis hands and feet. In thesemachines a project- :or chisel that is'driven'forward into the coalUNITED STATES PATENT OFFICE,

EBENEZ ER. HILL, OF SOUTH NORWALK, CONNECTICUT.

MINING-MACHINE.

SPECIFICATION formingpart of Letters Patent No. 261,608, dated July 25,1882.

Application filed February 17,1V882. (No model.)

useful Improvements in a Mining-Machine, of

which the following is a specification.

This invention is based upon the well-known mining-machines of oneHarrison, for which several patents have been grantedsince 1876,.

which pertains to a machine having a singlepiston engine supportedon apair of wheels and guided by an operator seated behind the ;ing end ofthepiston-rod'is armed with a pick bycompressed .air, used after-j themanner of steam acting upon the piston-arid I controlled by valves, asin the ordinary steam-engine. In

en forward by the air-pressure an equal amount of force is expended inthe opposite direction, which must be counterbalanced by the weight ofthe machine and the opposing resistance of the operator who is holdingand guiding it, and the recoil is similar to that of a gun',which mustbe sustained by the marksman, with addition, also, that as the pistonvibrates rapidly in opposite directions the recoil is constantly pushingand pulling, and hence the force of the blow and the speed of runningthe engine-arelimited by the power and endurance of the workman, andunder any circumstances are exceedingly severe and very injurious tohim.

To overcome these objections, and at the same time greatly increase theefficiency ofthe machine, is the object of this invention; and itconsists chiefly in combining two piston-cylinders with the samevalve-chamber in such a mannerthat the exterior ends of the pistonsconverge slightly toward each other, so that the pick or cutting-toolswill tend to the same point in the coal, and by suitablevalve-connections will exactly alternate with each other, or so that asone is movingforward the other will,with the approximately same amountof force, be withdrawn or move in the opposite direction, and therebyneutralize the tendency to recoil. Another advantage of such anarrangement is that, as the cylinders are placed nearly as far apart asthey are long, the pistons will reciprocate on the opposite sides of aplane, which will have a tendency to vibrate on a common centerequidistant from the wheels and at a right angle to their axis, so thatas each pick or tool is drawn out of the coal a prying action will beproduced, similar to the action of the common pick given by the minerwhen he'strikes into the coal and then lifts the handle; hence the coalwill, to a greater or less extent, be broken off in lumps, instead ofbeing pulverized or reduced in small chips.

Another feature of the invention consists in providing cushioning-headsin the ends of cylinders to receive the ends of the pistons in case thetool should miss or fail to strike the coal,

and thus prevent breaking the cylinder-heads. Thedrawings represent, atFigure 1, a verticalsection and partial elevation ofthe machine;

; and "Fig.2 'showsxa plan of, the same with the such mining-machines,when the piston is drivi plan of the valve as seen from the under side.

Fig. 4. is a diagram to show the position of the ends of the tools.v

The valve-chest A and the valve B are of a form similar to those used inthe Harrison machine, but of double the width to reach over the twocylinders C and D, which are placed under the valve-chest and at such anangleto each other as to makethe tools at E and F converge on tend tothe same point. s

The valve-operating mechanism is also the same as in the Harrisonmachine, consisting of a rotary engine, G, on the shaft of which is adisk, H, in the valve-chest and just below the throttle K, and aroundsaid disk is a rib, L,

inclined tothe axis, to work in a slot at L in the back of theslide-valve B to give it its proper motions; but the valve B is soconstructed that when one port is open to drive one of the pistonsforward the corresponding diagonally-opposite port of the other cylinderis open to drive the other piston back, and as the valve is formed ofthe same piece of metal and is operated by the same cam 'there is nopossibility of the pistons being in each others way.

A piston is shown at M, having a piston-rod at M, extending through astuffing-box at M and an extension is shown at M in a guidingsupport, Mand the tool is attached in the end of said extension of thepiston-rod,and fastened by a key at M, all of whichparts are made similar to thosein the Harrison machine. The same kind of guiding-handles N are alsoused, and the cylinders are supported on wheels at O in the same manner;but instead of bumpers or cushions of rubber for the piston to strikeagainst, as in the Harrison machine, I use disks of metal, 1?, in eachof the cylinders, which are larger in diameter than the bore of thecylinders, forming cushion-chambers. The ends of the cylinders areenlarged at R and bored to recei vethesedisks,thatwork nearly air-tight,or like pistonsin the said chambers, and their inner faces abut againstshoulders 1% at each end of the working-bore of the cylinders, andthereby serve practically as cylinder-heads to the piston-chambersproper.

From the valve-chambers small ports at S are formed, to let the air atfull pressure always remain behind said metal disks, so that they areheld against the shoulders R; but in case the tool misses the coal andis driven with full force toward the end of the cylinder the piston willfirst trap a small quantity of air between it and the disk to preventactual metallic contact, and the disk will then be driven back towardthe cylinder-head but the port at S, being very small, will not permit arapid escape of the air behind the disk, and hence it will be checkedbefore it can be driven against the cylinder-head. The pressure of theair between the disk and the head will, however, be greatly increased,and as the exhaust will be wide open the disk and the piston will bothbe driven back by the reactive force of the air so trapped, and the diskwill assume its place against the shoulders at the end of thepiston-cylinders proper.

The tools are made of the ordinary fish-tail form, as shown, and areplaced to work at a right angle to each other, as in the diagram at Fig.4. So they practically work as arevolvin g tool, or at least have thesame advantages, and owing to the vibratory motion of the machine, asalready explained, have somewhat the property of prying out the chips orlumps of coal.

The two cylinders might be placed close together and parallel to eachother to work the tools in holes independent of each other but in such acase this prying action would be lost, and, furthermore, the tools wouldnot have the advantages of striking into the coal from the oppositesides of the hole, and hence the lumps between the angles of the toolscould not be broken off.

I therefore claim- 1. In a mining machine, the combination of twopistons armed with cutting-tools, said pistons working in cylinderswhose axes converge toward the cutting-point, as hereinbefore described.

2. A mining-machine having the combination of two cylinders with thesame valvechest and a simultaneously-moving valve coverin g and openingdiagonally-located ports and operating two pistons inclined toward eachother, as hereinbefore set forth.

3. A mining-machine having the combination of two pistons slightlyinclined toward each other and carrying cutting-tools, mountedsubstantially as described, to have a vibratory action laterally or aprying action upon the material, as hereinbefore set forth.

4. A mining-machine having the combination of two pistons carryingcutters with fishtail or similar cutting-edges, arranged to work at aright angle to each other and converging to the same point, ashereinbefore set forth.

5. A mining-machine having, in combination with its workin g piston orpistons, a cushioning-chamber of larger diameter than the bore of thecylinder, and a disk to work in said chamber, with a small inlet-portbehind it, leading from the main valve-chest, as and for the purposesset forth.

In witness whereof ,I have hereunto set my hand and seal in the presenceof two subscribin g witnesses.

EBENEZER HILL. [L. s.]

Witnesses:

EUGENE N. ELIOT, AARON W. Wool).

